When a hunter kills their mother, two young grizzly bear cubs are taken into captivity. Now they must figure out how to break free to return to the sister they left behind. In 2006 the real-life Boo broke out of his enclosure, "smashing his way through a steel door, two electric fences and a 3.6-metre fence reinforced with 60 centimetres of steel sheet beneath the ground." Several weeks later, he returned of his own accord. This is the story behind his incredible escape and his remarkable decision to return.